Electrical apparatus



June 15, 1948. H. BENIOFF 2,443,179

' ELECTRICAL APPARATUS Filed June 24, 1941 2 Sheets-Sheet 1 55 INVENTOR H62 Y Hucao BENIOFF June 15, 1948. H-. BENIOFF 2,443,179

' ELECTRICAL APPARATUS Filed June 24, 1941 v 2 Sheets-Sheet 2 INVENTOR Hucao BENlOFF Patented June 15, 1948 ELECTRICAL APPARATUS Hugo Benioii, La Canada, Calif., assignor, by

mesne assignments, to Submarine Signal Company, Boston, Mass., a corporation of Delaware Application June 24, 1941, Serial No. 399,495

15 Claims.

The present invention relates to thermionic magnetron tubes of the type in which the tube element forms part of an oscillating circuit and is adaptable for use at extremely high radio frequencies in the range of 300 megacycles and higher, especially for high power. The invention herein described relates to that type of thermionic magnetron tube in which the tube elements themselves form parts of a resonant circuit. In particular, the anode is in the form of a cavity resonator of a toroidal shape having a concentric slot forming the mouth of the resonator. The cylindrical cathode is coaxial with the anode and mounted in relation-ship withthe anode slot as will be more fully understood in the specification below. The cooperating constant magnetic field is adjusted to such a value as to make the electron orbital frequency substantially equal to the resonant frequency of the anode cavity resonator. The direction of the magnetic field so created may be either parallel to the toroidal axis of revolution or parallel to the circular toroidal axis of revolution or even perpendicular to the toroidal axis of revolution. In these cases the electric field will be arranged perpendicular to the magnetic ,field and the resultant plane of the electron orbital frequency will be perpendicular to the magnetic field.

. The thermionic magnetron tube of the present type readily lends itself to constructions using a group of resonators which can be stacked axially to form multiple resonator systems.

. The invention will be more fully described in the specification below which is to be read in connection'with the drawings illustrating the invention in which Fig. '1 shows a vertical section,

through the center, of the tube; Fig. 2 shows a vertical section of themodification shown in Fig. l-in which a plurality of resonators are employed, the section being in relatively the same position asthe section of Fig.1; Fig. 3 shows a central section through amodified form of theinvention shown inFig. 1; Fig. 4 shows a similar central section through another modified form; Fig. 5 shows a section on the line 55 of Fig. l; and Fig. 6 shows a still further modified form in per-. spective of the invention shown in Fig. 1;

In the device illustratedin Fig. 1 the envelope 30 is preferably made of metal, cylindrical in form, with two fiat ends3| and 32 through the center of which pass the cathode heating leads 33 and 34 which are sealed to the end walls 3| and 32, respectively, by means of insulating glass seals 35 and 36 mounted on the ends of collars 31 and'38 extending from the fiat ends 3| and 2 32. Within the envelope 30 the leads 33 and 34 extend outward from the central axis into the arms 28 and 29 and support at their vertically extending ends brackets 39 and 40, respectively, by which the cathode 4| is supported. This cathode, as willbe seen in Fig. 5, is a ring to which current is con-ducted by the arms 39 and mat opposite ends of a diameter so that two.

halves of the ring are substantially connected in parallel across the leads 28 and 29. The cathode 4| also supports the top and bottom disc electron shields 21 and 26 by means of the brack-' ets 25 and 24 extending from the cathode 4| and supporting the electronshield discs 26 and 21 in position above and below the end-s of the cathode and overhanging the cathode outwardly in the direction of the anode resonator 42. These shields equalize the field potential about the top and bottom of the hot cathode and prevent electron emission in the direction of the bottom and, top covers 3| and 32, respectively.

The anode 42, as indicated in Fig. 1, is in the form a of a split hollow toroid with an annular slot 43 extending around the toroid concentric with the cathode .4| and preferably opposite the center. The back wall 44 of the toroid may be the wall of the envelope, the whole structure being substantially symmetrical withthe central axis of the toroid. The cavity 45 formed bythe wall 44 and the other toroidal walls is spaced from the end walls (Hand 32 and is placed at a positive potential as against the cathode 4| by means of the anode conductor 46 forming the central conductor of a concentric cable with the external conductor the conducting tube 41. This conductor 46 passes through an insulating glass seal through an opening 48 in the cavity 45 where it is connected to the wall 44 at 49, thus coupling with the high frequency cavity circuit oscillating at a resonance determined by the dimensions and operation of the device.

As illustrated in Fig. 1 a magnetizing field is established by the pole 50 which provides a cylindrical pole face over the end of the tube forming a north pole as indicated by the letter N at the top in conjunction with the pole 5| having a similar cylindrical pole face labelled S providing the south pole at the bottom side face of the tube. The envelope or housing isrexhausted of air by suitable means after which it may be sealed off at the pumping connection 52 in the glass seal 35. In Fig. 2 a multiple unit is indicated. In this case the metallic housing 53 is made of a longer cylinder as compared with that shown in Fig.1 but it has approximately the same diameter as connected across the cathode supply leads 6? and 88 which enter through the ends 54 and- 55th the unit in the collars 69 and 10 which are sealed ofi" with glass seals H and 12; Each cathode unit may also be supplied with end shields l3'and M as illustrated in Fig. 2. It will suiiice in the'con i-sfurnishedbye the elongated coil 88 in the center ofwhichthe magnetic field runs parallel to the axis of the coil.

. In the'arrangement shown'in Fig. 3 a modifiedform. of cavity resonator is shown. Here the tube assumes a. toroidal form- With the external walls at; 82, 83- and 8' 2 forming the toroid and the cavity resonator as twin chambers 85 andt-it' with a restricted -conducting passage 81' arranged betweeen the two cavities in the center of which ispositioned the cathode ring 881Which: is supported by the conductors 89 and 90' passing through the wall. 83 and sealed to the wall: by meansof the glass s'eals 9l and 91" in. connection withthe' extending necksfia and 94' which may formed as a partofthe walls 832 The cathodeheating current is s'uppliedthroug-h the leads 89 and 99. and the cathode-anode potential is supplied between the lea'ds 89 or- 90 and=the conductor 94: which: links the anode resonator by passing through the wall'of the resonator and being attached'tothe inner surface'of' the wall 84' at the point 95. As in the other-figures the conductor 9'1 is preferably continued externally of the tube in: a concentric cable.

Themagnetie fi'e1di s supplied-in the device indicated in Fig. 3 by means of the-magnet 91- which has a: cylindrical north pole'positi'oned H12 extends in a-horizontaljplane rather than as a vertical cylinder. 'Thecathode wtin-this case takes the form of a fiat ring in which' the cathodesurface is positioned iii-the plane of. the ring. The cathode-is supported by means of the current supply-leads HM and IUS' pass-ing through the top wall lllfiof'the resonator through the-tubes ml and H18 and the glass sealing elements4 b!) and 4' the Irr this case however; the neck betw'eenthe two twin chambers m1. and

H0 as described in connection with the previous figures. The anode lead Il'2 passes through the tube HI into the interior of the resonator I02 and is connected to one of the walls at the inside of the resonator as indicated in the figure. Some latitude is permitted as to the point of connection of the conductor H2. The conductor H2 is brought out eithe resonatoif-iria' concentric cable as illustrated in Fig. h In this arrangement the magnetic flux travels radially from a central 1 north pole core [L3 to a cylindrical south pole .-core- H l the core H3 being placed within the toroidal element and the cylindrical pole H4 being outside of: the element so that the lines of flux travel radiallyin the same plane or in parallel planes to the cathode I03.

In the arrangement shown in Fig. 6 a perspective iew of a further construction is illustrated in-wh-ich the coil 20 surrounds the resonating cavity 22 which has a slot 23 in the inside surface of the resonatorwall taking acylindrical form. The. cathode 21:- is the form: of at band or: ring: opposed to; the inner wall of the" cavity opposite the. slot just described. this construction magneticfield extends:- in a direction, paralleling the curve of they cathodell and the orbit .ofixthe electrons-fromthe 123511011811? inradialv planes perpendicular to; the cathode 'Havinginow described 'my-inventi-on', I claim;-

1.: A thermionic; magnetro'mztubeacomprisingg conductive means. having thereon a resonator shell forming. thei-anode otthe magnetromtube: and having a; ringslotiforming an openingin saidresonator: shell and". providing a: capacity across said openings... concentric cathode element? pasitionedin spaced: opposedrelation to. said slot and means for supplying a magnetic field having; its lines of force' ext-ending'in a.direetion-substan -r tia-lly perpendicular to the median: plane-ct the cathode, said 'ca thode being immersed int-said magnetic field; i

2: A thermionic magnetron tube comprising conductive means:havingthereinaresonatorshelll forming the anode of the' magnetron-tube and having a'ring' slot forming an opening in' 'said resonator shell-and providing-a capacity'across said. opening, a coaxialcathod'e elementsp'ac'ad; from said anode opposite said slo't and meansfor supplying a magneticvfield for: the space between the cathode andithe anode; said field extending ina direction perpendicular to the path of -theelectric fi'eld'between the cathodeand the anode}:

' 3. A\ thermionic magnetrontube comprisinga metallic cylindrical casing closedat both ends; a toroidal conductive resonatorshelI formi-ng the anode'of the; magnetron tube and having-one wall"- commomwith a wall 'of said -cy lindrical cas ingn sa-id' toroidal resonator: shell; having aririg slot therein. forming the mouth of the resonator shell on the inner sideof said resonator Shell a cathod member coaxial withsaida resonator: shell andmeanssupporting. and: positioning said cathode member in spaced opposed relationship? tosaidresonatorslotr 1 I 4. A thermionic magnetron. tobe comprisi-ngametallic cylindricar casing." closed? at I both ends, a toroidal conductiveiresona'tor shell forming-the anode of the magnetron: tubeandihaving one wall common" with a wall of: said cyI-in'drical' casing said toroidal resonator? shell: having a .ringslot";

therein forming the mouth; of" the resonatorishell on -the inner side-'of saidresonator shell; a cathode; member coaxial with saidiesonator shell-and. means supportingand: positioningAsaid; cathode: member in spacedopposed relationships'totsai'lh resonator slot, said supportingmeans being the conductive means for heating said cathode.

- 5. A thermionic magnetron tube comprising a metallic cylindrical casing closed at both'ends', a toroidal conductive resonator shell forming the anode of the magnetron tube and having one wall common with a wall of said cylindrical casing, said toroidal resonator shell having a ring slot therein forming the mouth of the resonator shell on the inner side of said resonator shell, a -cathode member coaxial with said resonator shell, means supporting and positioning said cathode member in spaced opposed relationship to said resonator slot and an electric shield supported from said cathode and extending over the ends of the cathode. v

6. A thermionic magnetron tube comprising a metallic cylindrical casing closed at both ends,- a toroidal conductive resonator shell forming the anode of the magnetron tube and having one'wall common with a wall of said cylindrical casing, said toroidal resonator shell having a ring slot therein forming the mouth of the resonator shell on the inner side of said resonator shell, a cathode coaxial with said resonator shell, means supporting and positioning said cathode in spaced opposed relationship to said resonator slot, said supporting means comprising two conductive members insulatingly sealed in said casing, said conductive members having elements supporting and providing electrical connections to said cathode at opposite sides of the said cathode.

7. A thermionic magnetron tube comprising a metallic cylindrical casing closed at both ends, a toroidal conductive resonator shell forming the anode of the magnetron tube and having one wall common with a wall of said cylindrical casing, said toroidal resonator shell having a ring slot therein forming the mouth of the resonator shell on the inner side of said resonator shell, a cathode ring coaxial with said resonator shell, means supporting and positioning said cathode ring in spaced opposed relationship to said resonator slot, said supporting means comprising two conductive members insulatingly sealed in said casing, said conductive members having elements supporting and providing electrical connections to said cathode at opposite ends of the same diameter of said cathode ring and an electric shield supported from said cathode and extending over the ends of said cathode.

8. A thermionic magnetron tube comprising a hollow cylindrical casing having both ends sealed, a plurality of coaxial toroidal conductive resonat-or shells positioned within said casing with the cylindrical wall of said casing forming one wall of each resonator shell and forming the anode of the magnetron tube, said resonators each having ring slots providing a mouth for each said resonator shell, said slots extending around the inner walls of said resonator shells, a plurality of cathode members coaxial with themselves and with said resonator shells, one cathode member positioned and spaced from each said slot in each of said resonator shells and means supporting said cathodes in said position within said casing.

9. A thermionic magnetron tube comprising a hollow cylindrical casing having both ends sealed, a plurality of coaxial toroidal conductive resonator shells positioned within said casing with the cylindrical wall of said casing forming one wall of each resonator shell and forming the anode of the magnetron tube, said resonators each having ring slots providing a mouth for each said resonator shell, said slots extending around the inner walls of said resonator-shells, a plurality of cathodemembers coaxial with themselves and with 'saidresonatorshells, one cathode member positioned and spacedirom each said slot in each of said resonator. shells and means supporting said cathodes in said position within said casing comprising a pair of conductive members supporting said cathodes at opposite ends of the same diameter for supplying current thereto.

10. ,A thermionic magnetron tube comprising a hollow cylindrical casing having both ends sealed, a plurality of coaxial toroidal conductive resonator shells positioned within said casing withthe cylindrical wall of said casing forming one wall of each resonator shell, and forming the'anode of the magnetron tube, said resonators each having ring slots providing a mouth for each said resonator shell,,said slots extending around the inner walls of,said resonator shells, a plurality of cathode members coaxial with themselves, and. with said resonator shells, one cathode member, positioned and spaced from each said slotin each of said resonator shells, means supporting said cathodes in said position within said casing and a plurality of electric shields supported and connected to said cathodes and extending over the ends thereof.

11. An ultra high frequency electric discharge device of the magnetron type, including a cathode, an electron-pervious anode member coaxial with and surrounding said cathode in spaced relation thereto, said anode member being substantially U-shaped in cross-section and being disposed with its cross-sectional configuration in a plane parallel to the axis of said cathode, means adjacent said anode member for establishing a magnetic field in the space between said anode member and said cathode, and means coupled to said anode member for extracting high frequency energy therefrom.

12. An ultra high frequency electric discharge device of the magnetron type, including an elongated cylindrical cathode, means adjaccnt said cathode for establishing a magnetic field parallel to the principal axis of said cathode, an electron-pervious anode structure comprising a substantially hollow conductive member of substantially U-shaped cross-section surrounding said cathode in spaced relation thereto, said anode member being disposed with its cross-section configuration in a plane parallel to said principal axis of said cathode, and means coupled to said anode member for extracting ultra high frequency energy therefrom.

13. An ultra-high frequency electric discharge device of the magnetron type, including an elongated thermionic cathode, means adjacent said cathode for establishing a magnetic field longitudinally of the axis of said cathode and adjacent thereto, an electron-pervious anode structure comprising a substantially hollow conductive member in spaced relation with respect to said cathode and having a U-shaped cross-section the open end of which faces said'cathode and lies in a plane parallel to the axis thereof, and output electrode means extending into said anode structure.

14. An ultra high frequency electric discharge device of the magnetron type, including a plurality of enclosed electrodes including an elongated cathode and a substantially hollow conductive anode member substantially surrounding said cathode and in spaced relation thereto, means adjacent said cathode and said anode member for establishing a magnetic field in the nmozmmw.

Number m8; 1945 AP FOREIGN PATENTS Country 

